MoparFins

December 13, 2017, 09:36:36 PM

Welcome, Guest

IMPORTANT: When we changed forum software, ALL passwords were lost! So please use the Forgot your password feature. If your email address has changed, use the Allpar "news tips" form to tell Dave about it and he will take care of you. We apologize for the inconvenience. (Your avatar may also have been lost but we hope not.

AuthorTopic: Polaraco vs, O2 Sensor (Read 612 times)

Have been having some MPG woes with Polaraco. I thought it was doing good, but I have been tracking it more lately. I have been using the car more daily lately so I remember what I fill it at. Instead of filling it every few weeks, I am filling it daily now. So I discovered a very disterbing problem.

The MPG has fallen way off. I am doing between 10 and 12 MPG mixed driving. Car runs great, but the O2 sensor is reading all over the planet, mostly on the rich side.

Yesterday I tried to see if I could find a 12V signal at the plug for the O2 heater. But found none. That same 12 Volt signal is spliced to other sensors and devices which are working normally. This O2 sensor is heated

I was wondering if anyone knew if there was a trick to checking the 12V signal at the O2 Sensor plug. I know it's the green and Orange wire.

OK... Here's where I feel bad since I haven't any parts books in front of me these days. Lemme test my memory.

I don't think you're supposed to find 12-volts at an O2 sensor. They kinda-sorta act as a battery, sending exhaust mix readings to a vehicles computer, telling it to lighten or enrichen the AF mixture. This is the reason only a diagnostic scan will detect a faulty one, as it gets no (or a weak) reading.

After going over the manual, the 12 Volts are only there when the engine is running. It has to have the crank and cam sensor seeing a signal for the ECM to send the heater 12VDC. The heater is to help the system get out of open loop faster, being more efficient on closed loop.

Steve,your O2 sensor,is it a 2-3-4 wire sensor?Do your O2 sensor reading range from .100-.900 and go from one end to the other fast or slow? Does the reading stay in one position for any amount of time?What type of scanner are you using to moniter the system,OTC,Snap-on,other,Mrmopartech